Photos: 2013 Blossom Kite Festival

2012 Cherry Blossom Pictures

"I think they misjudged it," another visitor said. "I think the cold weather threw them off, threw all of us off. Who thought we'd be dressed like this into April?"

The Park Service and the National Cherry Blossom Festival base their estimates on what they call an "indicator tree," a tree that they watch to gauge when the rest of the pink and white will blossom.

"The indicator tree has bloomed, so we are on the way," Danielle Piacente of the National Cherry Blossom Festival said. "Once the weather warms up, which it looks like its going to do at the end of the week, they'll pop out very quickly."

The blooming period and peak are two different things. By definition, the blooming period starts when 20 percent of the blossoms are open. But the peak doesn't hit until 70 percent of the trees are flowering.

Visitors along the Tidal Basin are hopeful that they'll see flowers soon -- but they remain skeptical.

"I started tracking yesterday, but today I see more white blossoms, hints of the lighter pink," said Aaron Soule of Dallas.

"Yesterday I could have believed it, but well have to wait and see," one visitor said.

"I wanted to see the blossoms, but I don't think theyre gonna open," said Susan Trainor, visiting from New Jersey.

And locals reminded the tourists: There's more to see in D.C. than the blooms.

"I think lots people will be disappointed, but they're here and there are many things to enjoy in D.C.," said Washington's Jerry Klepner, who spent the morning looking for pictures to take of the still-elusive blossoms.

When the blooms appear, we want to see your pictures! Tweet them to @nbcwashington with the hash tag #nbcblossoms